HC-020K is a high resolution, short response speed, wide voltage switch output speed
measuring module, with a black encoder can measure motor speed (Now provide the
encoder type D, hole diameter is 4 mm. Can be used to the output shaft is 4 mm motor).

Specifications:

• Working voltage: 4.5V to 5.5 V.
  
• Transmit tube pressure drop: Vf = 1.6 V
  
• Transmit tube current: 20 mA
  
• Signal output: A, B two way; The TTL level
  
• Distinguish precision: 0.01 mm
  
• Measurement frequency, 100 KHZ
  
• Encoder diameter: 24 mm
  
• Encoder type D hole diameter: 4 mm
  
• The encoder resolution: 20 line